Reference no: EM132595035

Question 1

A multimode fibre with a 50 μm core diameter is designed to limit the intermodal dispersion to 10 ns/km. What is the numerical aperture of this fibre? What is the limiting bit rate for transmission over 10 km at 0.88 μm? Use 1.45 for the refractive index of the cladding.

Question 2

A 0.88 μm optical communication system transmits data over a 10 km single mode fibre by using 10 ns pulses. The dispersion parameter of the fibre is D = 80 ps/(km-nm). The LED has a spectral width Δλ of 51 nm. Determine the maximum bit rate possible.

Question 3

A step index fiber with a large core diameter compared with the wavelength of the transmitted light has an acceptance angle in air of 22° and a relative refractive index difference of 3%. Estimate the numerical aperture and the critical angle at the core-cladding interface for the fiber.

Question 4

The mean optical power launched into an optical fiber link is 1.5 mW and the fiber has an attenuation of 6.5 dB km^-1. Determine the maximum possible link length without repeaters (assuming lossless connectors) when the minimum mean optical power level required at the detector is 2 μW.

Question 5

A 15 km optical fiber link uses fiber with a loss of 1.5 dB km^-1. The fiber is jointed every kilometer with connectors which give an attenuation of 0.8 dB each. Determine the minimum mean optical power which must be launched into the fiber in order to maintain a mean optical power level of 0.3 μW at the detector.